mophail



(No Model.) 2 Sheets-Sheet 1.

H. .MoPH AIL. APPARATUS FOR GENERATING STEAM.

No. 516,060. Patented Mar, 6, 1894.

(N0 Madam 2 Sheets-Sheet 2.

H. .MOPHAIL. APPARATUS FOR GENERATING STEAM.

' No. 516,060. Patented Mar. 6, 1894.

3 50 000 CC 20G 00G Nrrnn r'rnrns Farnlvr (lenient HUGH MCPHAIL, OF-W'AKEFIELD, ENGLAND, ASSIGNOR OF TlVO-THIRDS TO EDWVARD SIMPSON ANDCHARLES HENRY SIMPSON, OF SAME PLACE.

APPARATUS FOR GENERATING STEAM.

sSPECIFIOATION forming part of Letters Patent No. 516,060, dated March6, 1894.

Application filed June 27,1892. Serial No. 433,173.

(No model.) Patented in England June 11, 1892, No. 11,044; in y June19,1892,No-70,889: in France June 23,1892, No, 222,550; in Belgium June23,1892, N0.100,255: inItalyIebruary 1 1, 1893, XXVII, 33,518, and LXV,4'74; in Spain April 25, 1893,1iio. 14,382, and in Canada June14,1893,N0.43,221.

To aZZ whom it may concern.-

Be it known that I, HUGH MCPHAIL, a subject of the Queen of GreatBritain, and a resident of Wakefield, England, have invented a 5 certainnew and useful Improved Apparatus for Generating Steam and EvaporatingLiq-- uids, (for which I have obtained patents in Great Britain, No.11,044, dated J une 11,1892; in France, No. 222,550, dated June 23,1892; in

IQ Belgium, No. 100,255, dated June 23, 1892; in

Germany, No. 7 0,889, dated June 19, 1 892, patent of addition to No.53,988; in Italy XXVII, 33,518, LXV, 4.74, dated February 14, 1893; inSpain, No. 14,332, dated April 25, 1893, and

I 5 in Canada, No. 43,221, dated June 14, 1893,) of which the followingis a specification, reference being had to the accompanying drawings.

This invention. relates to certain improy e- 2o ments in apparatus forgenerating steam and evaporating liquids, and has for its chief objectsthe economical production of dry and superheated steam and theequalization of the temperature of the top and bottom of the boil- 2 5er in which the. steam is generated, thereby efiecting a bettercirculation. The said improvements also prevent priming.

For the economical production of power, and for other purposes, drysteam is a neceso sity, and various methods have been adopted to insurea supply of steam in that state, but these methods are not economical orare otherwise objectionable. It is also well known that in the varioustypes of boilers used for the 3 5 generation of steam, the water at thebottom is colder than that at the top; such difference in temperaturehas not onlyadeleterious effect upon the life of such boilers, but thesafety of the boilers is also endangered thereby; va-

4o rious methods have been adopted to obviate this serious defect.

According to this invention, the steam generated in the boiler is passedthrough the antipriming pipe or through one or more pipes or tubes tothe outside of the boiler, and is conducted into a suitable superheaterplaced in the internal flue or fines or in the external fine or times,or in the combustion chamber, or in such other location where they willbe subjected to a much higher temperature than that of the steam. Thesteam is thereby superheated. It is then conducted by means of pipes,tubes or coils through the water space of the boiler where it gives upits surcharged heat. The steam is then conducted through a secondsuperheater and may then be used or utilized, or again passed throughthe water space of the boiler. In the case of a Lancashire boiler forexample I prefer that the steam shall be conducted nearly the wholelength of the boiler toward the front end and back again in the waterspace below the internal flue tubes, which is, hitherto, the region ofthe lowest temperature of the boiler. The steam imparts its surchargedheat to the wa- 6 5 ter in the boiler at that level and therebyfacilitates the evaporation of the same, assisting in the equalizationof the temperature of the boiler, and effecting a more efficientcirculation than hitherto. The steam is then passed outside the boilerand into a second superheater, placed, for convenience, alongside thefirst, and again superheated or surcharged; it is then passed within theboiler through pipes as before for nearly the whole 7 5 length of theboiler and back again in the water space above the internal flue tubes,thereby further assisting in, or facilitating, the evaporation of thewater and improving the circulation. v

The invention comprises various improvements and advantages which I canmore conveniently explain, by means of the accompanying drawings,wherein Figure 1 is a horizontal central section of a 85 Lancashireboiler without the internal flue tubes. Fig. 2 is a similar sectionshowing the two fine tubes in position. Fig. 3 is a longitudinalsectional elevation of the same, showin g the flue tubes, the pipeswithin the boiler, 0 and the superheaters hereinafter described. Fig.4-. is a section on the line no, 03, Fig. 3. Fig. 5 is an elevation ofthe back end of the boiler and superheaters.

Throughout the drawings like letters indi- 5 cats corresponding parts.

The boiler shown is of the ordinary well known type of two finedLancashire. The

mountings and fittings are not shown as they are all of the ordinarydescription and are in no way affected by the adoption of myimprovements. It will also be observed that the adoption of myimprovements in no way interferes with eificient inspection of all theparts of the structure. The boiler is filled with water to the usuallevel and steam is raised by firing in the ordinary manner.

Instead of the steam passing from the boiler through the anti-primingpipe Z, direct to the stop valve, as hitherto, it is conveyed from thesaid pipe by means of pipes a and 17 into a superheater c placed at therear end of the boiler in the external flue where the temperature ismuch higher than that of the steam within the boiler; the steam istherein surcharged with heat by the heated gases which impinge upon thesuperheater. The steam then passes out of the superheater a, throughpipes at and e, into and along the boiler toward the front end and backbelow the flue tubes, that is to say, in the coldest part of the boilerand imparts some of the surcharged heat to the water surrounding thepipes d and e along which latter pipe the steam returns at the samelevel to a second superheater f placed alongside the first namedsuperheater. The steam is here again surcharged by being subjected tothe higher temperature of the gases. By means of pipe 9, the steam isthen again conveyed into the boiler and toward the front end thereof butthis time above the flue tubes still however below the water level, andis returned toward the back end by the pipe 71. It thus again impartssome of the surcharged heat to the water through the pipes g and h, thusfacilitating the evaporation of the water. The pipe h is connected tothe stop valve. From thence the steam is conveyed to the engine or isotherwise used for whatever purpose it is required. It will be observedthat the steam after entering the anti-priming pipe Z is never again incontact with the wa ter from which it has been generated, although asabove described it is conducted nearly the length of the boiler fourtimes and is taken outside the boiler twice, and superheated each time.

It is obvious that I may increase or dimin ish the number of times thesteam is carried into and out of the generator without departing from myinvention. Moreover instead of usingpipesforconductingthesteamImayemploy boxes, chambers, or coils. Thereare several very important advantages as a result of this arrangement,viz:

First. There is no priming. Priming is a cause of great inconvenienceand annoyance to the engineer, as it is difficult at all times toascertain its cause and still more difficult under ordinary arrangementsto prevent its occurrence, and it is generally admitted that primingaccounts for much loss in .efficiency in practice.

Second. The production of dry steam, that is to say, steam from whichall aqueous or watery particles formerly held in suspension have beenconverted into steam proper.

Third. The steam passing through the stop valve is superheated or sorcharged that is to say, the steam in addition to being dry has itstemperature raised above that due to the corresponding pressure ofsaturated steam.

Fourth. By my improved arrangements I am enabled to materially reducethe difierence between the temperature of the top and bottom of theboiler and thereby not only facilitate the circulation and evaporationof the water but add to the longevity and safety of the boiler.

Fifth. The advantages above enumerated together with the quickerproduction of steam are effected much more economically by theconsumption of less fuel than hitherto.

My improved arrangements can be applied to any boiler, that is to say,it is not necessary to construct a boiler of a new type in order tocarry out my invention. Not only to Lancashire two flued, but toCornish, ma rine, multitubular, locomotive, vertical, water tube andother well known types of boilers this invention can be applied, and notonly for the raising of steam but for the evaporation of liquids forother purposes.

What'I claim is- 1. In combination with a steam generator, pipes leadingfrom the steam space of the generator to a superheater placed in theflue of the generator, and other pipes from such superheater passingthrough the water space of the generator to a second superheater, forthe purpose specified, that is to say, whereby the steam from thegenerator is superheated in the said superheater and then passed throughthe Water space of such generator in the said other pipes which are indirect contact with the water in the generator throughout the whole orsubstantially the whole of their course and then conducted to the secondsuperheater, substantially as described.

2. The combination with a steam generator, of pipes leading from thesteam space of the generator to a superheater in the flue thereof, asecond superheater, pipes leading from the first superheater through thewater space of the generator to the second superheater, and pipesleading from the second superheater through the water space of theboiler, whereby the steam from the generator is superheated in the firstsuperheater, then passed through the water space of the generator, thenconducted to the second superheater, and then again passed through thewater space of the boiler, to be used or utilized, substantially asdescribed.

In witness whereof I have hereunto set my hand this 13th day of June,1892.

H. MOPHAIL.

Witnesses:

GEO. HARRISON, EBEN SHEFFIELD.

l'IO

